Why is it dangerous to drive alongside large commercial vehicles?

• Because they have large blind spots
• Because they are big enough to block your sight
• Because if the commercial vehicle stop and you’re behind it then you have nowhere to go
• All of above
  Explanation:

  "Large commercial vehicles have big blind spots on both sides. Avoid tailgating a large vehicle. The driver cannot see you if you are directly behind. If the vehicle stops suddenly, you have no place to go. Remember that if you can't see the driver’s face in the large vehicle’s side-view mirror, the driver cannot see you"